Solving liner systems use the substitution method to sovle the liner system
1. y=x-4
4x+ y = 0
2007-03-29 03:05:13 · 10 answers · asked by SIANI S 1 in Education & Reference ➔ Homework Help
When you plug the first equation into the second you get...
4x + x - 4 = 0
Solve for x and you get 4/5
Then plug 4/5 into x in either equation and you will find that y = -16/5
Your answer is...
x = 4/5
y = -16/5
You can check it by plugging the numbers into either equation.
2007-03-29 03:21:14 · answer #1 · answered by bigbit22 3 · 0⤊ 1⤋
If y=x-4
and 4x+y=0
To do substitution, I do believe you have to mix them problems.... like so:
first make the problems have one letter equal the other.
y=x-4 is okay.
4x+y=0 is not.
if 4x=-y+0.... then x=-y/4, correct? (you know the drill on the number-switching in algebra... how that goes, hopefully XD)
Well, if y=x-4 and x=-y/4, then it would be safe to say that the "x" in the y=x-4 is equal to.... well.... x!
So the problem would now be y= -y/4-4!
And now you can do the rest of the problem!
(I sure hope I was thinking of the right substitution method. I probably was. ;-D)
2007-03-29 10:38:42 · answer #2 · answered by ? 3 · 0⤊ 0⤋
y=x-4 : 4x+y=0
start with first equation since you know what y = in that equation. Plug what y= in the first equation into the y in the 2nd equation.
So you have
y=x-4 -----> 4x+y=0 -----> 4x+(x-4)=0
simplifiy it now.
4x+(x-4)=0 ------> 5x-4=0
add 4 to both sides
5x=4
To solve for x divide both sides by 5
(5x/5) = (4/5)
x=4/5
now take the value of x and sub it back into the first equation (y=x-4) and solve for y.
y=x-4 -------> y=(4/5) - 4
y=(4/5)-(20/5) because 4=(20/5)
y= -16/5
so you have x=4/5 and y=-16/5
now its time to check your answer.
so you plug x and y back into the equation that is set to 0
4x+y=0 ------> 4(4/5) + (-16/5) = 0
(16/5) + (-16/5) = 0
0=0
so the equation balances out and you have your correct answer.
again: x=4/5 and y= -16/5
i must admit, i don't know why you would've put Pi in the title, it has nothing to do with linear systems.
2007-03-29 10:28:32 · answer #3 · answered by Greg O 3 · 0⤊ 0⤋
4x+ (x-4)=0 that simplified into 4x+x -4=0 add your x to get 5x-4=0 add 4 to both sides 5x=4 divide by five to get x=4/5
then plug that back in for y to get y=4/5-4 so y= -3 1/5 wirte your answer as an ordered pair so it would be (4/5, -3 1/5)
2007-03-29 11:17:37 · answer #4 · answered by angel_babydoll_devil08 2 · 0⤊ 0⤋
5x = -4
you can check it out here, this site can help with your homework, show you how to the problems are worked out. But the answer maybe the least numerator for the problem. As with this one answer come out to be
x = 4/5 and y = -16/5
with this you'd have to make sure to divide to get the correct answer.
2007-03-29 10:27:13 · answer #5 · answered by Lana 3 · 0⤊ 0⤋
Are you sure you type this in right? The answers I get don't match up. I got x = 1 and y = -3, but when I double check, they don't match.
2007-03-29 10:09:48 · answer #6 · answered by Anonymous · 0⤊ 2⤋
5x= -4 you can solve it from here
2007-03-29 10:09:12 · answer #7 · answered by theca_va 3 · 0⤊ 1⤋
3.14 when rounded to the second decimal point.
2007-03-29 10:14:39 · answer #8 · answered by Snaglefritz 7 · 0⤊ 1⤋
WAT IS UP I READ THAT BOYS BOYS BOYSA THING U MADE THAT STORY UP I KNOWN IT THE ANSWER IS I DONT KNOW
2007-03-30 10:53:09 · answer #9 · answered by DESI 1 · 0⤊ 0⤋
www.mathhelp.com
2007-03-29 10:08:48 · answer #10 · answered by Anonymous · 0⤊ 1⤋